The present invention relates to a spring suspension device between frame part or chassis part and wheel-bearing part of a vehicle, for example a motorcycle. In this connection, a vehicle is intended, in which the suspension of the bearing part relative to the frame/chassis is dependent upon the loading of the wheel or wheels which are arranged in the bearing part. The invention relates inter alia to a spring suspension device in a motorcycle or similar vehicle, which comprises a frame, relative to which a rear fork bearing a rear wheel is rotatably mounted.
Spring suspension devices of said type have been in existence for a long time in a great number of variants, usually in combination with some form of shock absorption. Helical springs made of metal with hydraulic shock absorbers can be considered as standard in this connection, but torsion suspension has also been proposed.
Said constructions, in general, function well under ordinary conditions of use, that is to say driving on normal roads. If greater demands are made, however, for example in competitions over country terrain with a motorcycle, there are such great demands for suspension characteristics adapted to the weight and driving style of the rider and the nature of the terrain that the abovementioned constructions do not meet the demands.
The object of the invention is therefore to bring about a suspension of the type mentioned in the introduction, which results in a low centre of gravity on the vehicle, especially the motorcycle. Moreover, the suspension is also to be able to exhibit low weight and simple construction and permit simple adjustability of a wide range of suspension characteristics.
The invention is also to be able to operate effectively in interaction with the shock absorption function so that space-saving arrangements can be designed. It is especially important in the case of motorcycles that the space behind the frame and in front of the rear wheel can be divided for accessory equipment (tank, battery etc.).
The suspension and shock absorber device is also to be able to contribute to easier and more adaptable frame construction since it is possible to reduce the material in the frame.